WO2006070889A1 - Electric power steering device - Google Patents
Electric power steering device Download PDFInfo
- Publication number
- WO2006070889A1 WO2006070889A1 PCT/JP2005/024142 JP2005024142W WO2006070889A1 WO 2006070889 A1 WO2006070889 A1 WO 2006070889A1 JP 2005024142 W JP2005024142 W JP 2005024142W WO 2006070889 A1 WO2006070889 A1 WO 2006070889A1
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- WO
- WIPO (PCT)
- Prior art keywords
- internal
- teeth
- external gear
- external
- electric power
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
- B62D5/0421—Electric motor acting on or near steering gear
- B62D5/0424—Electric motor acting on or near steering gear the axes of motor and final driven element of steering gear, e.g. rack, being parallel
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
- B62D5/0442—Conversion of rotational into longitudinal movement
- B62D5/0445—Screw drives
- B62D5/0448—Ball nuts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
- F16H55/02—Toothed members; Worms
- F16H55/17—Toothed wheels
- F16H55/171—Toothed belt pulleys
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H7/00—Gearings for conveying rotary motion by endless flexible members
- F16H7/02—Gearings for conveying rotary motion by endless flexible members with belts; with V-belts
- F16H7/023—Gearings for conveying rotary motion by endless flexible members with belts; with V-belts with belts having a toothed contact surface or regularly spaced bosses or hollows for slipless or nearly slipless meshing with complementary profiled contact surface of a pulley
Definitions
- the present invention relates to a ball screw type, separate shaft type rack assist type electric power steering apparatus.
- an electric power steering apparatus Electric Power Steering, hereinafter referred to as EPS
- EPS uses an in-vehicle battery as the power source of the electric motor, and since the electric motor with no direct engine drive loss is started only at the steering assist, it can suppress the decrease in driving fuel consumption, and also has electronic control. It has the feature that it can be done very easily.
- a rack pion type is currently mainstream because of its high rigidity and light weight.
- the EPS for rack and pion type steering gears includes a column assist type with an electric motor on the side of the column to drive the steering shaft, and an electric ball screw mechanism.
- a ball screw type rack assist type that drives the rack shaft is also used.
- the assist force does not act on the mating surface between the pion and the rack, the contact surface pressure between both members, which causes wear and deformation, is relatively small.
- the male screw groove and ball of the ball screw shaft formed on the rack shaft are engaged via a number of circulating balls (steel balls), and the ball nut is driven to rotate by an electric motor arranged coaxially with the rack shaft or on a separate shaft. As a result, the rack shaft moves in the axial direction.
- the power transmission mechanism is driven by an electric motor and has a small-diameter external gear having external teeth, and the external gear is inscribed.
- a ring-shaped internal gear having internal gears that mesh with each other and supported so as to be swingable around the axis of the external gear, a driving pulley provided on the outer peripheral surface of the internal gear, and a belt formed by the driving pulley.
- a ball screw mechanism that is driven by the driven pulley and moves the rack shaft.
- Patent Document 1 after the speed is reduced by the external gear and the internal gear, the speed is reduced by the driving pulley and the driven pulley, and the reduction ratio can be increased in two stages. Even if the speed reduction mechanism is not required, or the driven pulley is not increased in diameter, the reduction mechanism as a whole can be reduced in size and achieve a high reduction ratio, and can be easily mounted on a vehicle. Also, since it is not necessary to reduce the radius of curvature of the belt winding region around the driving pulley, the belt life can be extended.
- Patent Document 1 Japanese Unexamined Patent Application Publication No. 2004-262264 (WO 2004/069631 A1)
- the present invention has been made in view of the circumstances as described above, and provides an electric power steering device that can improve the durability of teeth and reduce operating noise and operating torque. For the purpose.
- an auxiliary steering torque is generated from the electric motor, and the auxiliary steering torque is transmitted to the rack shaft of the steering mechanism via the power transmission mechanism.
- the power transmission mechanism is
- a ring-shaped internal / external gear having internal teeth that are inscribed in mesh with the external gear, supported so as to be swingable about the axis of the external gear, and having an outer peripheral surface acting as a driving pulley, and the internal / external gear A driven pulley driven via a belt,
- a ball screw mechanism that is driven by the driven pulley and moves the rack shaft
- a circular support is provided substantially coaxially,
- an electric power steering device characterized in that an annular support for supporting the circular support is provided on an end portion of the internal / external gear substantially coaxially and inscribed with the circular support.
- the outer diameter of the circular support is set substantially equal to the pitch circle diameter of the inner teeth of the external gear
- An electric power steering device is provided in which the inner diameter of the annular support is set substantially equal to the pitch circle diameter of the internal teeth of the internal and external gears.
- the circular power support and the annular support have a movement restricting mechanism for restricting the axial movement of the internal and external gears.
- the outer diameter of the circular support is set substantially equal to the pitch diameter of the external gear
- An electric power steering device is provided in which the inner diameter of the annular support is set substantially equal to the pitch circle diameter of the internal teeth of the internal and external gears.
- the movement restricting mechanism is configured such that one of the contact portions of the circular support and the annular support is formed in a convex shape and the other is formed in a concave shape. Is provided.
- the movement restricting mechanism is provided with an electric power steering device characterized in that the shape of the contact portion between the circular support and the annular support is formed in a tapered shape so as to be opposed and symmetrical.
- An electric power steering apparatus wherein a flange is provided on a side portion of the internal / external gear.
- An electric power steering device is provided in which the flange is formed integrally with the annular support provided at an end of the internal / external gear.
- the external teeth of the external gear, the internal teeth of the internal and external gears and the outer peripheral surface combined teeth, the combined teeth of the belt, and the outer peripheral surface combined teeth of the driven pulley are set to bevel teeth
- the twist angle of the internal teeth of the internal and external gears is ⁇
- the twist angle of the outer peripheral surface meshing teeth of the inner and outer gears is ⁇
- the meshing pitch circle radius of the internal teeth of the internal and external gears is r
- a lower steering device is provided.
- An electric power steering device characterized by being used for four-wheel steering rear wheel steering is provided.
- An electric power steering apparatus is provided that is used for steer-by-wire steering in which the steering wheel and the rack shaft are not mechanically connected.
- a circular support is provided on the end of the external gear substantially coaxially, and the circular support is supported on the end of the internal and external gears in a coaxial manner.
- An annular support is provided.
- the radial force of the tension acting on the drive pulley can be supported by the circular support and the annular support, and both gears can only handle torque transmission.
- the radial force due to the belt tension does not act on both gears, and the inner and outer gears do not bite into the outer gear. Therefore, the durability strength of the teeth can be improved and the operating noise and operating torque can be reduced.
- the outer diameter of the circular support is set substantially equal to the pitch circle diameter of the outer gear
- the inner diameter of the annular support is set substantially equal to the pitch circle diameter of the inner teeth of the inner and outer gears. It is. For this reason, the contact portion between the circular support and the annular support is not rolled in contact with sliding. Since contact occurs, an increase in operating torque due to friction can be minimized.
- the circular support and the annular support have the movement restricting mechanism that restricts the axial movement of the internal and external gears, and the movement restricting mechanism includes the circular support and the annular ring.
- the shape of the contact portion with the support one is formed in a convex shape and the other is formed in a concave shape.
- the concavo-convex shape has, for example, different radii of curvature, and the contact portion has a contact form that is close to a point contact.
- the frictional wear can be remarkably reduced by the rolling contact of the contact portion with a small area (substantially point contact).
- the movement restricting mechanism is formed so that the contact portions of the circular support and the annular support face each other in a tapered shape and are symmetrical.
- the contact portion is close to point contact and has a contact form. As a result, since the contact portion makes rolling contact with a small area (substantially point contact), friction and wear can be remarkably reduced.
- the flange is provided on the side portion of the internal and external gears to restrict the axial movement of the belt. This prevents the belt from moving in the axial direction and touching the housing, thereby preventing an increase in operating torque, a decrease in durability, and abnormal noise.
- the flange is formed integrally with the annular support provided at the end of the internal and external gears, means for attaching the flange separately is omitted, and the thickness of the mounting portion is reduced. Is possible and has the effect of making the structure compact.
- the belt mesh teeth and the outer peripheral surface mesh teeth of the driven pulley are set as oblique teeth, and the twist directions of these oblique teeth are set to be the same direction.
- the twist angle of the internal teeth of the internal and external gears is ⁇ , and the outer periphery of the internal and external gears
- the twist angle of the face meshing teeth is ⁇ , and the meshing pitch circle radius of the internal teeth of the internal and external gears is r.
- the meshing pitch circle radius between the outer peripheral surface gear teeth of the inner and outer gears and the belt gear teeth is r.
- the force for axially moving the internal and external gears generated from the meshing of the external teeth of the external gear and the internal teeth of the internal and external gears is set to be equal, and as a result, the axial movement of the inner and outer gears is restricted.
- FIG. 1 is a longitudinal sectional view of an electric power steering apparatus of a ball screw type and another-shaft rack assist type according to an embodiment of the present invention.
- FIG. 2 is a cross-sectional view along the line A—A (dashed line side) in FIG.
- FIG. 3 is a cross-sectional view taken along line BB (two-dot chain line side) in FIG.
- FIG. 4 is a longitudinal sectional view of a ball screw type separate-axis rack assist type electric power steering apparatus according to a second embodiment of the present invention.
- FIG. 5 is an enlarged cross-sectional view showing, in an enlarged manner, a contact portion between a circular support and an annular support according to a second embodiment of the present invention.
- FIG. 6A An enlarged cross-sectional view showing a contact portion between a circular support and an annular support according to a modification of the second embodiment of the present invention.
- FIG. 6B is an enlarged cross-sectional view showing, in an enlarged manner, a contact portion between the circular support and the annular support according to a modification of the second embodiment of the present invention.
- FIG. 6C is an enlarged cross-sectional view showing, in an enlarged manner, the contact portion between the circular support and the annular support according to a modification of the second embodiment of the present invention.
- FIG. 7 is an enlarged cross-sectional view of a main part of a ball screw type separate-shaft rack assist type electric power steering device according to a third embodiment of the present invention.
- FIG. 8 is a longitudinal sectional view of a ball screw type separate-axis rack assist type electric power steering device according to a fourth embodiment of the present invention.
- FIG. 9 is a longitudinal sectional view of a ball screw type separate-axis rack assist type electric power steering device according to a fifth embodiment of the present invention.
- FIG. 10A is an enlarged cross-sectional view of the circular support and the annular support shown in FIG.
- FIG. 10B is an enlarged cross-sectional view of a circular support and an annular support according to a sixth embodiment of the present invention.
- FIG. 10C is an enlarged cross-sectional view of a circular support and an annular support according to a seventh embodiment of the present invention.
- FIG. 11 is a vertical cross-sectional view of a ball screw type separate-shaft rack assist type electric power steering apparatus according to an embodiment of the present invention.
- FIG. 12A is a schematic diagram showing an enlarged view of a meshing portion of the external gear, the internal / external gear, and the belt shown in FIG. 11.
- FIG. 12B The meshing pitch line (X) between the external teeth of the external gear and the internal teeth of the internal and external gears is indicated by a broken line, and the meshing pitch line of the external surface meshing teeth of the internal and external gears and the meshing teeth of the belt (Y) FIG.
- FIG. 1 is a longitudinal sectional view of an electric power steering device of a ball screw type and a separate axis type rack assist type according to an embodiment of the present invention.
- FIG. 2 is a cross-sectional view taken along the line AA (dotted line) in FIG.
- FIG. 3 is a cross-sectional view taken along the line BB (two-dot chain line side) in FIG.
- housings 1, 2, 3 (steering gear cases) are provided, and an electric motor 4 is attached to the nosing and udging 1.
- the pivot shaft 7 is spline-fitted to the concave end portion of the drive shaft 5 of the electric motor 4.
- the pivot 7 is rotatably supported on the housings 1 and 2 by bearings 8 and 9.
- a small-diameter external gear 11 having external teeth is formed on the pivot shaft 7. As shown in FIG. 2, a ring-shaped internal / external gear 12 having internal teeth is meshed with the external gear 11.
- the internal and external gears 12 are supported so as to be swingable about the axis of the external gear 11, and the outer peripheral surface acts as a driving pulley (that is, the outer peripheral surface of the internal and external gears 12 has , Belt to be described later
- a belt 14 having meshing teeth on the inside is provided. It's hanging over.
- a rack shaft 21 is accommodated so as to be movable in the axial direction, and the rack shaft 21 is provided with a ball screw mechanism including a ball nut 22. It is.
- the rack shaft 21 is formed with a male screw groove 23, while the ball nut 22 is formed with a female screw groove 24.
- a circular ball is formed between the male screw groove 23 and the female screw groove 24.
- a large number of steel balls 25 are interposed.
- the ball nut 22 is provided with a circulation top (not shown) for circulating the steel ball 25.
- the ball nut 22 is supported by a double row bearing 26, and is connected so that the driven pulley 13 can rotate together with the ball nut 22 at a spline portion 28 provided on the cylindrical body 27 at the end thereof. is there.
- circular support bodies 31 are provided on both ends of the outer gear 11 on substantially the same axis, and both ends of the inner and outer gears 12 are provided.
- a circle on the same axis An annular support 32 that supports the support 31 inwardly is provided.
- the radial force of the tension acting on the outer peripheral surface of the internal / external gear 12 can be supported by the circular support 31 and the annular support 32, and both the gears 11 and 12 can transmit only torque. Can take charge.
- the radial force due to the belt tension does not act on the gears 11 and 12, and the inner and outer gears 12 do not bite into the outer gear 11. Therefore, the durability strength of the teeth can be improved and the operating noise and operating torque can be reduced.
- the circular support 31 has an outer diameter set substantially equal to the pitch circle diameter of the outer gear 11
- the annular support 32 has an inner diameter of the pitch circle diameter of the inner teeth of the inner / outer gear 12. Is set approximately equal to. Therefore, the contact portion between the circular support 31 and the annular support 32 becomes a rolling contact rather than a contact with slipping, so that an increase in operating torque due to friction can be minimized.
- the inner / outer gear 12 is not provided with a flange, and the bearing that supports the driven pulley 13 when the belt 14 rotates and moves in the axial direction. N Sides of the belt 14 may come into contact with the housings 1 and 2.
- the circular support 31 and the annular support 32 include an internal and external gear.
- Embodiments having a movement restricting mechanism that restricts twelve axial movements will be described in detail as second to fourth embodiments.
- the circular support 31 and the annular support 32 have a movement restricting mechanism that restricts the axial movement of the inner and outer gears 12.
- the outer peripheral surface of the circular support 31 is formed in a concave arc shape, and the inner peripheral surface of the annular support 32 is a convex arc shape. Is formed.
- the external gear 11 is rotated by the rotation of the drive shaft 5 of the electric motor 4, and the rotation thereof. Is transmitted to the inner / outer gear 12 and is transmitted to the driven pulley 13 via the belt 14.
- the belt 14 tends to move in the axial direction due to the orientation and inclination of the core wire, the twist of the belt 14 itself, and the like.
- the internal / external gear 12 also attempts to move in the axial direction by the rotational force of the belt 14.
- the outer peripheral surface of the circular support 31 is formed in a concave arc shape
- the inner peripheral surface of the annular support 32 is formed in a convex arc shape
- the internal / external gear 12 Is always pressed in the direction of the driven pulley 13 by the belt tension.
- the concavo-convex arc shape plays a role of guiding, and the axial movement of the internal / external gear 12 can be restricted, and the contact between the internal / external gear 12 and the housings 1, 2, etc. can be avoided.
- the concavo-convex shape has, for example, different contact radii, and the contact portion between the circular support 31 and the annular support 32 has a contact form close to point contact.
- the frictional wear can be remarkably reduced by the rolling contact of the contact portion with a small area (substantially point contact).
- the uneven shape of the circular support 31 and the annular support 32 only needs to be able to regulate the axial movement of the internal / external gear 12.
- the concavo-convex shape of the circular support 31 and the annular support 32 is not necessarily a curved surface, but may be formed so as to be in contact with a substantially obtuse angle.
- the circular support 31 and the annular support 32 may have the directions of the concave and convex arc shapes reversed.
- a plurality of contact portions in an uneven arc shape may be provided.
- FIG. 7 is an enlarged cross-sectional view of a main part of a ball screw type, separate-axis rack assist type electric power steering apparatus according to a third embodiment of the present invention.
- the circular support 31 and the annular support 32 are arranged so that the internal and external gears 12 move in the axial direction. It has a movement regulation mechanism that regulates movement.
- the contact portions of the circular support 31 and the annular support 32 are opposed to each other as a tapered shape, and are formed symmetrically.
- the shape of the contact portion between the circular support 31 and the annular support 32 is tapered.
- the internal and external gears 12 are always pressed against the driven pulley 13 by tension.
- the contact portion with 32 is in a contact form that is close to point contact. Accordingly, the frictional wear can be remarkably reduced by the rolling contact of the contact portion with a small area (substantially point contact).
- FIG. 8 is a longitudinal sectional view of a ball screw type, separate-axis rack assist type electric power steering apparatus according to a fourth embodiment of the present invention.
- the meshing teeth on the outer peripheral surface of the internal / external gear 12 and the meshing teeth on the outer peripheral surface of the driven pulley 13 provided coaxially with the rack shaft 21 described later are meshed inward.
- An inclined belt 41 having teeth is stretched over.
- the inclined tooth belt 41 When the rotation of the internal / external gear 12 is transmitted to the driven pulley 13 via the inclined tooth belt 41, the inclined tooth belt 41 has the inclined tooth angle, the direction and inclination of the core wire, the twist of the inclined tooth belt 41 itself, etc. Tries to move in the axial direction. Also in the present embodiment, when the inclined belt 41 tries to move in the axial direction, the outer peripheral surface of the circular support 31 is formed in a concave arc shape, and the outer peripheral surface of the annular support 32 is The inner and outer gears 12 are always pressed in the direction of the driven pulley 13 by the belt tension.
- the concavo-convex arc shape plays a role of guiding, the axial movement of the internal / external gear 12 can be restricted, and the contact between the internal / external gear 12 and the housings 1, 2, etc. can be avoided.
- the concave and convex shapes of the concave and convex shapes are, for example, different contact radii, and the contact portions of the circular support 31 and the annular support 32 and the contact portions are substantially close to point contact. As a result, the frictional wear can be significantly reduced by the rolling contact of the contact portion with a small area (substantially point contact).
- flanges for restricting axial movement of the belt are provided on both sides of the internal and external gears. I will explain.
- the external gear 11 is rotated by the rotation of the drive shaft 5 of the electric motor 4, and the rotation is transmitted to the internal / external gear 12 and is transmitted to the driven pulley 13 via the belt 14.
- the belt 14 tries to move in the axial direction due to the orientation and inclination of the core wire and the twist of the belt 14 itself. If the belt 14 is an inclined belt (not shown), the belt 14 moves in the axial direction depending on the angle of the inclined teeth.
- the bell A flange 40 is provided to restrict the axial movement of the G14.
- FIG. 10B is an enlarged cross-sectional view of a circular support and an annular support according to the sixth embodiment of the present invention.
- the flange 40 is formed integrally with the annular support 32 provided at the end of the internal / external gear 12.
- the flange 40 is formed integrally with the annular support 32, the means for attaching the flange separately can be omitted, and the thickness of the attachment portion can be reduced. It has the effect of making the structure compact.
- FIG. 10C is an enlarged cross-sectional view of a circular support and an annular support according to the seventh embodiment of the present invention.
- the flange 40 is formed integrally with the annular support 32 provided at the end of the internal / external gear 12.
- the flange 40 is formed integrally with the annular support body 32, means for attaching the flange separately can be omitted, and the thickness of the attachment portion can be reduced. It has the effect of making the structure compact.
- the circular support 31 and the annular support 32 have a movement restricting mechanism that restricts the axial movement of the internal / external gear 12.
- the movement restricting mechanism is The outer peripheral surface is formed in a concave arc shape, and the inner peripheral surface of the annular support body 32 is formed in a convex arc shape.
- the outer peripheral surface of the circular support 31 is formed in a concave arc shape
- the inner peripheral surface of the annular support 32 is formed in a convex arc shape
- the inner / outer gear 12 is always driven side It is pressed against the pulley 13 by the belt tension.
- the concavo-convex arc shape serves as a guide, and the axial movement of the inner / outer gear 12 can be restricted, and contact between the inner / outer gear 12 and the housings 1, 2, etc. can be avoided. Accordingly, an increase in operating torque and a decrease in durability due to sliding contact can be suppressed, and abnormal noise can be prevented.
- the concavo-convex shape has, for example, different radii of curvature, and the contact portion between the circular support 31 and the annular support 32 has a contact form close to point contact.
- the frictional wear can be remarkably reduced by the rolling contact of the contact portion with a small area (substantially point contact).
- the uneven shape of the circular support 31 and the annular support 32 only needs to be able to restrict the axial movement of the internal / external gear 12.
- the concavo-convex shape of the circular support 31 and the annular support 32 may be a concavo-convex shape that is not a curved surface, and may be formed so as to be in contact with a substantially obtuse angle.
- the circular support 31 and the circular support 32 may have reverse concave and convex arc shapes.
- the external teeth of the external gear, the internal teeth of the internal and external gears and the outer peripheral surface of the external teeth in the above-described first to seventh embodiments, the toothed teeth of the belt, and the teeth of the outer peripheral surface of the driven pulley are: In the first to third embodiments, examples using straight teeth have been described, but inclined teeth may be used as in the fourth embodiment. (Eighth embodiment)
- those teeth are set as oblique teeth, and the twisting directions of the inclined teeth are set in the same direction.
- the embodiment will be described in detail below.
- FIG. 11 is a longitudinal sectional view of an electric power steering device of a ball screw type and another-shaft type rack assist type according to an embodiment of the present invention.
- FIG. 12A is an enlarged view of the meshing portion of the external gear, the internal / external gear, and the belt shown in FIG. FIG. 12B shows a meshing pitch line (X) between the external teeth of the external gear and the internal teeth of the internal / external gear by a broken line
- FIG. FIG. 5 is a schematic diagram showing the mating pitch line as a solid line (Y).
- the external teeth of the external gear 11, the internal teeth 12a and the outer peripheral surface meshing teeth 12b of the internal and external gear 12, the meshing teeth of the belt 14, and the driven pulley 13 The peripheral teeth of the outer teeth are set to be inclined teeth, and the torsional directions of these inclined teeth are set to be the same direction.
- a tangential force (Fa) is generated in the internal / external gear 12 due to the meshing between the external teeth of the external gear 11 and the internal teeth 12a of the internal / external gear 12.
- a tangential force (Fb) is generated in the inner / outer gear 12 due to the engagement between the outer peripheral surface meshing teeth 12b of the inner / outer gear 12 and the meshing teeth of the belt 14.
- the axial direction moving force for axially moving the internal / external gear 12 generated from the meshing between the external teeth of the external gear 11 and the internal teeth 12a of the internal / external gear 12, and the internal / external gear 12 The axial movement force for axially moving the internal / external gear 12 generated by the meshing of the outer peripheral surface meshing teeth 12b of the belt 14 and the meshing teeth of the belt 14 can be set to be opposite to each other. As a result, the axial movement of the inner / outer gear 12 can be restricted.
- twist angle of the internal teeth 12a of the internal / external gear 12 is ⁇ , and the outer peripheral surface of the internal / external gear 12 is meshed.
- the tangential force (Fa, Fb) is also the torque force acting on the mating part, respectively.
- Equation (1) Equation (1) becomes
- the axial movement of the internal / external gear 12 can be restricted, and an increase in operating torque and a decrease in durability can be suppressed, and the occurrence of abnormal noise can be prevented.
- the electric power steering device described above may be used to steer the front wheels like a normal steering mechanism, and may be used to steer front wheels or rear wheels of a four-wheel steering mechanism. It is natural.
- the present invention can also be applied to a so-called steer-by-wire (SBW) type steering in which the steering wheel and the rack shaft are not mechanically connected.
- SBW steer-by-wire
- the present invention also includes a combination of the first to eighth embodiments.
- the radial force of the belt tension acting on the internal and external gears can be supported by the circular support and the annular support, and both gears receive only torque transmission. Can have. Therefore, the radial force due to the belt tension does not act on both gears, and the internal and external gears do not bite into the external gear. Therefore, an electric power steering apparatus that can reduce the operation noise and the operation torque with high tooth durability is provided.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Power Steering Mechanism (AREA)
- Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
- Gear Transmission (AREA)
- Transmission Devices (AREA)
- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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JP2006520501A JPWO2006070889A1 (en) | 2004-12-28 | 2005-12-28 | Electric power steering device |
US10/586,365 US20070151794A1 (en) | 2004-12-28 | 2005-12-28 | Electric power steering apparatus |
DE112005003002T DE112005003002T5 (en) | 2004-12-28 | 2005-12-28 | Electric power steering device |
Applications Claiming Priority (8)
Application Number | Priority Date | Filing Date | Title |
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JP2004-381681 | 2004-12-28 | ||
JP2004381681 | 2004-12-28 | ||
JP2005-017257 | 2005-01-25 | ||
JP2005017257 | 2005-01-25 | ||
JP2005022075 | 2005-01-28 | ||
JP2005-022075 | 2005-01-28 | ||
JP2005082230 | 2005-03-22 | ||
JP2005-082230 | 2005-03-22 |
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WO2006070889A1 true WO2006070889A1 (en) | 2006-07-06 |
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PCT/JP2005/024142 WO2006070889A1 (en) | 2004-12-28 | 2005-12-28 | Electric power steering device |
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US (1) | US20070151794A1 (en) |
JP (1) | JPWO2006070889A1 (en) |
DE (1) | DE112005003002T5 (en) |
WO (1) | WO2006070889A1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2010179891A (en) * | 2009-02-09 | 2010-08-19 | Jtekt Corp | Electric power steering device |
DE102014112253A1 (en) | 2013-08-29 | 2015-03-05 | Jtekt Corporation | STEERING DEVICE |
JP2016055830A (en) * | 2014-09-12 | 2016-04-21 | 株式会社ショーワ | Steering device |
JP2016084011A (en) * | 2014-10-24 | 2016-05-19 | アイシン精機株式会社 | Rear wheel steering device for vehicle |
JP2016203758A (en) * | 2015-04-21 | 2016-12-08 | アイシン精機株式会社 | Rear wheel steering device of vehicle |
CN110578779A (en) * | 2018-06-08 | 2019-12-17 | 操纵技术Ip控股公司 | durable power unit belt drive |
US11192416B2 (en) * | 2017-07-07 | 2021-12-07 | Zf Friedrichshafen Ag | Adjusting device for a chassis of a motor vehicle and rear-axle steering system |
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- 2005-12-28 DE DE112005003002T patent/DE112005003002T5/en not_active Withdrawn
- 2005-12-28 WO PCT/JP2005/024142 patent/WO2006070889A1/en not_active Application Discontinuation
- 2005-12-28 US US10/586,365 patent/US20070151794A1/en not_active Abandoned
- 2005-12-28 JP JP2006520501A patent/JPWO2006070889A1/en not_active Withdrawn
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JP2003074680A (en) * | 2001-09-03 | 2003-03-12 | Hirabayashi Seisakusho:Kk | Gear meshing structure |
JP2003312496A (en) * | 2002-04-25 | 2003-11-06 | Nsk Ltd | Motor-driven power steering gear |
JP2004262264A (en) * | 2003-02-03 | 2004-09-24 | Koyo Seiko Co Ltd | Electric power steering device |
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Cited By (8)
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JP2010179891A (en) * | 2009-02-09 | 2010-08-19 | Jtekt Corp | Electric power steering device |
DE102014112253A1 (en) | 2013-08-29 | 2015-03-05 | Jtekt Corporation | STEERING DEVICE |
JP2016055830A (en) * | 2014-09-12 | 2016-04-21 | 株式会社ショーワ | Steering device |
JP2016084011A (en) * | 2014-10-24 | 2016-05-19 | アイシン精機株式会社 | Rear wheel steering device for vehicle |
JP2016203758A (en) * | 2015-04-21 | 2016-12-08 | アイシン精機株式会社 | Rear wheel steering device of vehicle |
US11192416B2 (en) * | 2017-07-07 | 2021-12-07 | Zf Friedrichshafen Ag | Adjusting device for a chassis of a motor vehicle and rear-axle steering system |
CN110578779A (en) * | 2018-06-08 | 2019-12-17 | 操纵技术Ip控股公司 | durable power unit belt drive |
CN110578779B (en) * | 2018-06-08 | 2023-06-20 | 操纵技术Ip控股公司 | Durable power unit belt drive |
Also Published As
Publication number | Publication date |
---|---|
DE112005003002T5 (en) | 2007-10-18 |
JPWO2006070889A1 (en) | 2008-06-12 |
US20070151794A1 (en) | 2007-07-05 |
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